1. Field of the Invention
The present invention relates to an inspecting apparatus for inspecting a coating state of a coating agent such as a soldering paste applied to an electronic circuit including an IC (Integrated Circuit) and an electronic component obtained by packaging the electronic circuit, a mounting apparatus equipped with the inspecting apparatus, an inspecting method therefor, and a method of mounting an electronic component using the inspecting method.
2. Description of the Related Art
In a production process of electronic components, a surface mounting method is used as one type of a method of mounting an electronic component. In the surface mounting method, an electronic component is connected to a substrate and the like via bumps (protrusions for electrical connection) provided on a package body thereof, for example. Here, because the bumps are coated with a coating agent such as a soldering paste, it is necessary to precisely control a coating state (coating amount or range) of the coating agent with respect to the bumps. This is because, when the surface mounting component is joined to the substrate and the like, an excessively-large amount of soldering paste causes a bridge and an excessively-small amount of soldering paste causes a connection failure.
Japanese Patent Application Laid-open No. 2006-19380 (paragraph [0040]) (hereinafter, referred to as Patent Document 1) discloses an apparatus for coating bumps with a coating agent, inspecting a coating state of the coating agent, and mounting a circuit device on a substrate. In the apparatus disclosed in Patent Document 1, a liquid agent such as the coating agent is transferred onto a bump of an electronic component by a liquid agent transfer apparatus, and the bump onto which the liquid agent has been transferred is imaged by an imaging apparatus. A distribution modal luminance (luminance with the most pixels at the same luminance) for each unit section is acquired from the image obtained by the imaging, and by comparing the acquired distribution modal luminance with that acquired by previously measuring a sample (circuit device judged that a liquid agent transfer amount thereof is adequate), it is judged whether the liquid agent transfer amount is adequate.